Patent GB-995509-A (GB)
Title: Method and apparatus for assembling and fastening laminations
IPC: H02K15/02
Filed: 1963-03-04
Abstract: 995,509. Assembling dynamo-electric motor stators; riveting machines. A. E. CHAMBERS. March 4, 1963, No. 8501/63. Headings B3A and B3U. An apparatus for making a laminated assembly comprises a delivery shoot containing a number of apertured laminae in excess of that required for an assembly, and a mandrel engaging the laminae internally and supporting beyond the end of the shoot at least the number of laminae required for an assembly, the mandrel itself being supported by reason of its engagement with the laminae within the shoot. Construction.-A feed shoot 28 receives from a stamping press, laminations 30 of the form shown in Fig. 2. A mandrel 40 fits inside the stamping and has a roller 44 and portion 48 which is reduced in thickness and in width. Displacement of the laminµ through the shoot is opposed by a pressure pad 50 mounted on a crosshead 52 connected to the piston-rods 54 of hydraulic cylinders 55. The crosshead runs on guide rods 53 which form part of the main frame 21, 22, 23. A clamping crosshead 60 also slides on the guide rods and comprises two fluidoperated cylinders 82 each containing a piston 79 having a piston-rod 78 carrying a clamping element 80. One cylinder is larger in diameter than the other so that the laminations are always held in the same relative position. The crosshead 60 is longitudinally displaceable on the guide rods 53 by means of fluid cylinders 64. A riveting yoke 90 is mounted on the frame for sliding movement between a withdrawn position (solid lines in Fig. 4) and an inner position (dotted lines in Fig. 4) in which a pair of rivet holding elements 100 are aligned with rivet receiving holes 38 in the laminµ. The yoke also carries anvils 94 which abut the leading end of the rivet. The rivets are transferred from the holders 100 to the stack of laminations and are riveted over therein by staking hammers 110 carried by the piston 111 of a fluid pressure cylinder 112. The sequence of operations is controlled by limit switches operating hydraulic valves through relays and solenoids so that each operation commences as the previous operation is completed. Operation.-Laminµ are fed into the shoot 28 against the pressure of the pad 50 and over the mandrel 40. As feeding continues the laminae project from the forward end of the shoot and are supported by the mandrel. When the leading lamination contacts a limit switch the clamping cylinders are energized and move in to grip the laminµ. The length of the clamping elements 80 and also of the reduced portion 48 of the mandrel is equal to the desired length of the stack of laminations. Due to the inward deformation of the laminations under the clamping load only those laminae positioned over the reduced portion of the mandrel are free to be withdrawn as the crosshead 60 is moved to the left in Fig. 1. This movement is initiated by the pressure build-up in the hydraulic line feeding the clamping cylinders, after the clamps have engaged the laminµ. The crosshead 60 strikes a limit switch which energizes the hydraulic cylinders 55 and retracts the pressure pad 50. When it reaches the retracted position the crosshead 52 operates a limit switch which actuates an hydraulic cylinder 120 to move the riveting yoke transversely of the axis of the shoot 28 to align the rivet holders 100 with the rivet holes 38. The riveting yoke operates a further limit switch which energizes the cylinder 111 and causes the hammers 110 to push the rivets out of the holders 100, through the work and against the anvils 94. At the end of the riveting stroke the pressure in the line feeding the cylinder 111 rises and operates a switch which reverses the valve controlling the cylinder 111 and retracts the hammers. When the piston 113 reaches the end of its travel a pressure switch is operated by the subsequent rise in line pressure, the clamp cylinders are released to allow the riveted assembly to fall into a trough, and the riveting yoke is returned to its withdrawn position. The pressure pad cylinders 55 then move the pressure pad 50 to the right in Fig. 1 which pushes the mandrel 40 back into the stack of laminae within the shoot and presents the pressure pad 50 to the leading lamination in order to provide the resistance necessary to form a closely-packed stack of laminations.